中文摘要：

红外锁相热成像技术是一种基于热波信号处理的主动式红外热成像技术，特别适用于复合材料及复杂结构构件的无损检测。阐述了红外锁相热成像技术的原理，采用有限元方法对正弦规律变化的热流在构件中的传递过程进行了分析。利用正弦规律调制光源作为热激励源对不同材料的试件加载，通过JadeMWIR550焦平面红外热像仪进行图像序列的采集，深入研究了图像序列数字滤波算法，并采用Savitzky—Golay数字平滑滤波算法消除了高频噪声的影响，在此基础上，利用FFT算法得到了热波信号的幅值与相位图像，并采用VisualC＋＋平台开发了基于图像序列处理的红外锁相软件检测系统。试验结果表明，通过选取适当的激励加载频率可准确获得缺陷特征。

英文摘要：

Lock-in thermography is an active infrared thermography technology which is based on thermal wave processing and surface temperature analysis. It is especially suitable for the non-destructive test of subsurface defects of composite materials and compound structure component. The principle of lock-in thermography was described, and the FEM was used to investigate the behavior of thermal waves in homogeneous plates with several holes in subsurface as defects and the plate with a finite thickness under convective conditions. In experimental study, the lamp with sine modulated law was used for active heat source into sample, and the image sequences of thermal wave were collected with Jade MWIR 550 FPA infrared thermography. The digital filter algorithm was researched and Savitzky-Golay digital smooth falter algorithm was used to reduce high frequency noise signal. And then the FFT transform algorithm was researched to obtain the image of amplitude and phase of thermal wave on the surface of sample. The program of IR lock-in thermography was developed by Visual C ＋＋ development platform. The experimental results show that the selecting proper excited frequency can acquire the defect characters.